Flashcards
Module 16
Flashcards do conjunto (12)
- 1EXPLAIN COMPACT DISC(CD) STORAGE MEDIUM & TYPES?OVERVIEW OF A COMPACT DISK:
- released in the early 80s
- portable storage medium for video, audio, & other data (allowed to record, store, playback)
- more room on a compact disc than floppy disc but still prone to damage
- CD-ROM works with light reflectors from lasers(as long as it had two different ways to reflect that laser then this is how you could translate those two reflective states to a 1 or 0)
DIMENSIONS AND DESIGN:
- diameter: 4.7 inches or 120 millimeters
- weight: 15 gram to 20 gram
- storage: 650 to 700 MB
COMMON TYPES:
- CD-Read-Only(original version, came with data already on it & couldn't be changed)
- CD-Recordable(blank disk, can write on disk once and read many times)
-CD-ReWritable(can overwrite(need a CD burner which used the laser to alter the chemical state of the disc itself to write/rewrite 1 or 0))
- CD-ROM eXtended Architecture(allowed multiple types of data on the same disks .e.g. audio, video & data)
- (CDV)CD for Video(usually had the MPEG file format - had high resolution & allowed the video to be stored in an uncompressed state(650/700MB) - 2EXPLAIN DVD & KEY FEATURES?DIGITAL VERSATILE DISK(DVD):
- may refer to as a digital video disc
(as mainly used for this purpose)
- another type of optical disc storage(1995)
- common DVD formats:
DVD-R & DVD+R(R=recordable)(- & + only compatible with their own sign, if it has both are a '?' in between then both are supported)
DVD-RW, DVD+RW, and DVD-RAM(recordable, writable/rewritable, RAM = data written like a hard drive from track to track than normal writing in one long spiral track - also didn't need specific software installed like others to work with the format)
- adopted early by movies and home entertainment industry(replaced VHS) & gaming consoles
KEY FEATURES:
- stores many kinds of data(audio/video, data)
- original DVD can't store high definition video(HD DVD can)
- manufacturing costs dropped loads
- cheaper than newer technology such as Blu-ray
- shares the same dimensions as compact discs
DVD CAPACITY:
- standard diameter(12cm)
- standard capacity(4.7 GB)
- dual-layer capacity(can vary laser intensity to read layer 1 & 2, doubling capacity to 8.5-8.7GB)
- data transfer rates(1.4 to 33.2 MB/s) - 3EXPLAIN BLU-RAY DISC?BLU-RAY DISK:
- another digital optical disc data storage format(uses the blue laser as blue light has a higher frequency compared to red, translating into a more tightly focused beam, hence more data on disc)
- replacement for DVD's
- supports HD & Ultra HD content
- primarily used for movies & video games
- shares common dimensions with DVDs & CDs (12cm diameter 1.2mm thickness)
VARIANTS OF DISC:
- Blu-ray Disc recordable(can rewrite over existing data)
- Mini Blu-ray Disc(8cm, so more compact but less data)
- BD9(able to work with 8.5GB size specification) & BD5(only 4.7 GB),(backward compatible as Blu-ray info can be written to DVD media)
-IH-BD(intra-hybrid, is 1 layer that's only readable & the other writable)
-BDXL(referred to as extra-large, introducing a 3rd & 4th layer for increased capacity)
STORAGE CAPACITY:
- single layer(120mm, 25GB)
- dual-layer(120mm, 50GB)
- XL 3 layer(120mm, 100GB)
- XL 4 layer(120mm, 128GB) - 4EXPLAIN SSD?SOLID-STATE DRIVES(SSD):
- persistent memory storage(doesn't need the power to retain data(non-volatile))
- data stored on an in integrated circuit(not a magnetic spinning disk)
- no mechanical components
- much faster access compared to traditional hard drives
- offers greater shock resistance
- improved storage performance(faster in accessing data, reading & writing data, shorter boot times, faster application launching, faster file transfer - as no need to locate the appropriate place on the disc as it's written on a chip somewhere)
KEY CHARACTERISTICS:
- less fragmentation(as the location of the data does not matter compared to hard drives)
- little operating noise(as no moving parts)
- more compact than hard drives
- requires less power to operate
KEY LIMITATIONS:
- pricey compared to other options
- most commonly used SSDs have capacities under 1TB(can be bigger but more expensive)
- provide little warning of impending failure
- shorter life cycle than HDD
- unsuitable for archiving - 5EXPLAIN MAGNETIC HDD?MAGNETIC HARD DISK DRIVES
- electromechanical data storage device(has moving parts)
- uses rapidly rotating magnetic platters(least 2 perhaps 4, each platter has a top and bottom surface so for every platter you have 2 storage surfaces
- has actuator arm(reads/writes data, applying an electrical charge to the magnetic platter)
- data is randomly accessed(but the disc has to spin to correct locations to access data, so does not perform as well)
-non-volatile storage(doesn't need power to retain data)
KEY CHARACTERISTICS:
- mature technology, highly reliable in storing data for 10/15 years, cost-effective, high capacity, common interface for an internal hard drive is Serial ATA interface
PERFORMANCE:
performance varys greatly depending on platter rotation speed(5400 vs 7200(modern speed) rpm(revolutions per minute - faster it spins, faster you locate), internal cache(uses a bit of memory to act as a temporary storage location while data is being written or read), interface type(Serial ATA is more common)
- magnetic hard disc drives underperform SSD's
- High capacity than SSD - 6Explain 2.5-inch vs 3.5-inch Drives?- these are the most common physical sizes for hard drives
3.5 INCH HARD DRIVE
- commonly used in desktop computers
- easy to install
- cost-effective
- generally find a high capacity compared to 2.5-inch drive(2-4 TB is common)
- generally have higher data transfer rates(faster platter rotation speed & more cache as more physical space in the unit)
2.5 INCH HARD DRIVE
- commonly used in laptops
- can be used in desktops(but challenging to install as you need a type of adapting bracket for it to fit in the larger drive bay)
- makes very little noise
- smaller capacity(under 2 TB common)
- generally lower data transfer rates(due to slower platter rotation speed & less cache) - 7EXPLAIN HYBRID DRIVES?HYBRID DRIVES:
-Is a combination of solid-state drive and the traditional magnetic hard drive
- offers SSD speed
-HDD capacity
- middle ground in terms of cost
- since SSD costs have dropped in recent years it's not as common to find a hybrid now
HOW IT WORKS:
- has both SSD & HDD within a single device
- small SSD(the smaller section where the operating system and the most frequently accessed data would be stored)
- traditional HDD (find the more infrequently accessed data, large media/documents, etc)
KEY FEATURES:
- software caching algorithm(keeps track of most often used resources)
- caching algorithm resides in hybrid drives firmware(so the operating system doesn't see two separate sections of the drive, it automatically allocates data to SSD and HDD)
- nonvolatile SSD cache
- with this algorithm, the speed will improve overtime as it learns(ends up faster than HDD but slower than SSD, but use to cost less than SDD) - 8EXPLAIN FLASH DRIVES?OVERVIEW OF FLASH DRIVES:
- uses a type of memory known as electrically erasable programmable read-only memory(so you can write to it then erase that, and rewrite to it, and then read many times from it)
- nonvolatile memory
- offers very fast access time(as it's just a collection of memory chips)
- shock-resistant and durable
- relatively cheap
KEY USES:
- short term data storage(just in the regard that they are easy to lose, so not the best backup), data partibility, in some systems it can be used for RAM(random access memory) enhancement, can sometimes implement multi-boot configurations
COMMON DEVICES:
- USB flash drives(memory sticks)
- CompactFlash(CF, often in cameras/printers)
-SECURE DIGITAL CARD(SD)(superseded CF, also comes in 2 different sizes, MiniSD Card & MicroSD)
- xD-Picture Card(was common for cameras, largely replaced by SD) - 9EXPLAIN HOT-SWAPPABLE DRIVE MEDIA?HOT SWAPPABLE DRIVES:
- refers to the fact that you can quite literally replace a physical hard drive in a system without powering down
- you'll have a Hot Swappable Bay which is permanently attached to the computer(mounted to it, power and data connections attach to the back of the bay), then you'll slide the hard disc into the Bay and it makes the connections at the back of the bay, making it usable again without having to power down.
- hot-swap ability is a common concept, virtually every USB device is hot-swappable
- hot-swap ability in internal hard drives is far more common in service systems than it is in desktops because servers tend to have a lot of hard drives(as it makes it easy to take out a failed without having to take that server down and interrupt all of its other functionality
-Supported for SSD & HDD but dependent on the interface(SCSI, Serial Attached SCSI & Serial ATA support it, IDE does not)
FEATURES:
- ideal for storage and archiving of data
- full drives & faulty drives can be swapped out without interruption
- provides high availability and high reliability - 10EXPLAIN TYPES OF RAID?OVERVIEW OF REDUNDANT ARRAY OF INDEPENDENT DISCS
- is a hard drive configuration that allows you to have multiple physical drives, operating as a single logical unit
- various RAID levels(r allow you to configure redundant and non-redundant configurations)
- reliable data storage(meant to continue to service that data even though one of your physical discs may fail)
- fairly low-cost implementation
- common on systems with multiple hard drives such as servers(also commonly used with hot-swappable configurations)
- often in found in server world - 11EXPLAIN CATEGORIES OF RAID & RAID 0 - STRIPING?CATEGORIES:
- software-based RAID(]using the hard drives that are physically there in the computer, along with the inherent management interface of the operating system itself. Can be configured into a RAID array, just using that inherent administrative interface, is cheaper)
- hardware-based RAID(means you go out & actually purchase a physical controller card & all of the hard drives connect to that card, then there's usually software that comes with the card that you install separately, & that's how you manage devices). This is preferred in most cases as there's a lot of cache memory on the card that can help to speed up access to the drive, & usually support more physical devices than what you might have on the computer(offers more functionality) - 12EXPLAIN RAID 0 - STRIPING?RAID 0 - STRIPING:
- has levels(commonly supported levels by most operating systems of 0, 1, 5, & a relatively new one of 1 plus 0)
- RAID 0 is known as striping, & the 0 indicates there's actually no redundancy(this allows you to write & read from both discs simultaneously, but no redundancy doesn't protect you from single disk failure)
RAID 1 - MIRRORING:
-completely duplicates the files on one physical disc over to another one, providing redundancy as you can replace the failed disc, regenerate the mirror & still have all of your original data
RAID 5: STRIPING WITH PARITY:
- parity, in this case, means there's some kind of error connection, so still striping to get good performance, but parity information allows you to actually recover data if its loss
RAID 1+0 - STRIPE OF MIRRORS:
-sometimes referred to as RAID 10
- has two individual mirror sets that are then striped(striping does not give you redundancy, but it does give you very good performance, so by adding in the mirror sets, then we have redundancy too)
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- Learning Technology Specialist CompTIA A+ (Core 1) FlashCards sobre Module 16, criado por Chantelle Knight em 11-09-2021.
- Criado por
- Chantelle Knight
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